CHIRALITY FROM MIRROR SYMMETRIC PLASMONIC NANOSTRUCTURES

ADDISALEM SHIFERAW

dc.contributor.author	ADDISALEM SHIFERAW
dc.date.accessioned	2020-12-23T11:54:37Z
dc.date.available	2020-12-23T11:54:37Z
dc.date.issued	2020-12-23
dc.identifier.uri	http://hdl.handle.net/123456789/11749
dc.description.abstract	Chirality is at the origin of life and existing in nature. A system is named chiral if it is nonsuperimposable with its own mirror image. Such object interacts with left and right circularly polarized lights differently. The differential absorption (response) of right and left circularly polarized light is called Circular Dichroism (CD). Finite Difference Time Domain (FDTD) simulation method used to calculate max well equation. The purpose of this work, we are known the chiral molecular sensing of two gold and one iron nano disks. The conventional understanding in physics, chemistry, and biology is that circular dichroism results from either an internal chiral structure or external symmetry breaking by illumination. We theoretically demonstrate the existence of chirality in two dimensional and geometrically mirror symmetric trimer nanostructures. iron oriented at the left side of the trimer nano disks, the value of circular dichroism was different from zero (CD = 1.8%) but, the value of circular dichroism becomes zero when iron placed at the center of the trimer nano-disks. The trimer which contains same size two gold and one iron nanodisks were arranged symmetrically which met the conditions of structural mirror superimposable. The optical scattering at the fundamental resonance is characterized numerically using Finite Difference Time Domain (FDTD) simulation method. In this approach the chiral optical response is induced by the heterogeneous material selection. The existence of iron makes the structure heterogeneous materially and the trimer act as super-chiral and enables the emergence of near and far field CD in the visible regime. The result brings a paradigm shift in understanding about the origin of chirality in science. Besides, the simplicity and generality, this finding reveal a whole new significance of the electromagnetic design and complex media engineering at a nanoscale with potential far-reaching implications for optics in biology, chemistry and materials science. Keywords: Chirality, Circular dichroism, FDTD, Gold and Iron nano sphere	en_US
dc.language.iso	en	en_US
dc.subject	Physics	en_US
dc.title	CHIRALITY FROM MIRROR SYMMETRIC PLASMONIC NANOSTRUCTURES	en_US
dc.type	Thesis	en_US